The present invention relates to a system for controlling a model railroad.
Model railroads have traditionally been constructed with of a set of interconnected section""s of train track, electric switches between different sections of the train track, and other electrically operated devices, such as train engines and draw bridges. Train engines receive their power to travel on the train track by electricity provided by a controller through the track itself. The speed and direction of the train engine is controlled by the level and polarity, respectively, of the electrical power supplied to the train track. The operator manually pushes buttons or pulls levers to cause the switches or other electrically operated devices to function, as desired. Such model railroad sets are suitable for a single operator, but unfortunately they lack the capability of adequately controlling multiple trains independently. In addition, such model railroad sets are not suitable for being controlled by multiple operators, especially if the operators are located at different locations distant from the model railroad, such as different cities.
A digital command control (DDC) system has been developed to provide additional controllability of individual train engines and other electrical devices. Each device the operator desires to control, such as a train engine, includes an individually addressable digital decoder. A digital command station (DCS) is electrically connected to the train track to provide a command in the form of a set of encoded digital bits to a particular device that includes a digital decoder. The digital command station is typically controlled by a personal computer. A suitable standard for the digital command control system is the NMRA DCC Standards, issued March 1997, and is incorporated herein by reference.
While providing the ability to individually control different devices of the railroad set, the DCC system still fails to provide the capability for multiple operators to control the railroad devices, especially if the operators are remotely located from the railroad set and each other.
DigiToys Systems of Lawrenceville, Ga. has developed a software program for controlling a model railroad set from a remote location. The software includes an interface which allows the operator to select desired changes to devices of the railroad set that include a digital decoder, such as increasing the speed of a train or switching a switch. The software issues a command locally or through a network, such as the internet, to a digital command station at the railroad set which executes the command. The protocol used by the software is based on Cobra from Open Management Group where the software issues a command to a communication interface and awaits confirmation that the command was executed by the digital command station. When the software receives confirmation that the command executed, the software program sends the next command through the communication interface to the digital command station. In other words, the technique used by the software to control the model railroad is analogous to an inexpensive printer where commands are sequentially issued to the printer after the previous command has been executed. Unfortunately, it has been observed that the response of the model railroad to the operator appears slow, especially over a distributed network such as the internet. One technique to decrease the response time is to use high-speed network connections but unfortunately such connections are expensive.
What is desired, therefore, is a system for controlling a model railroad that effectively provides a high-speed connection without the additional expense associated therewith.
The foregoing and other objectives, features, and advantages of the invention will be more readily understood upon consideration of the following detailed description of the invention, taken in conjunction with the accompanying drawings.
The present invention overcomes the aforementioned drawbacks of the prior art, in a first aspect, by providing a system for operating a digitally controlled model railroad that includes transmitting a first command from a first client program to a resident external controlling interface through a first communications transport. A second command is transmitted from a second client program to the resident external controlling interface through a second communications transport. The first command and the second command are received by the resident external controlling interface which queues the first and second commands. The resident external controlling interface sends third and fourth commands representative of the first and second commands, respectively, to a digital command station for execution on the digitally controlled model railroad.
Incorporating a communications transport between the multiple client program and the resident external controlling interface permits multiple operators of the model railroad at locations distant from the physical model railroad and each other. In the environment of a model railroad club where the members want to simultaneously control devices of the same model railroad layout, which preferably includes multiple trains operating thereon, the operators each provide commands to the resistant external controlling interface, and hence the model railroad. In addition by queuing by commands at a single resident external controlling interface permits controlled execution of the commands by the digitally controlled model railroad, would may otherwise conflict with one another.
In another aspect of the present invention the first command is selectively processed and sent to one of a plurality of digital command stations for execution on the digitally controlled model railroad based upon information contained therein. Preferably, the second command is also selectively processed and sent to one of the plurality of digital command stations for execution on the digitally controlled model railroad based upon information contained therein. The resident external controlling interface also preferably includes a command queue to maintain the order of the commands.
The command queue also allows the sharing of multiple devices, multiple clients to communicate with the same device (locally or remote) in a controlled manner, and multiple clients to communicate with different devices. In other words, the command queue permits the proper execution in the cases of: (1) one client to many devices, (2) many clients to one device, and (3) many clients to many devices.
In yet another aspect of the present invention the first command is transmitted from a first client program to a first processor through a first communications transport. The first command is received at the first processor. The first processor provides an acknowledgement to the first client program through the first communications transport indicating that the first command has properly executed prior to execution of commands related to the first command by the digitally controlled model railroad. The communications transport is preferably a COM or DCOM interface.
The model railroad application involves the use of extremely slow real-time interfaces between the digital command stations and the devices of the model railroad. In order to increase the apparent speed of execution to the client, other than using high-speed communication interfaces, the resident external controller interface receives the command and provides an acknowledgement to the client program in a timely manner before the execution of the command by the digital command stations. Accordingly, the execution of commands provided by the resident external controlling interface to the digital command stations occur in a synchronous manner, such as a first-in-first-out manner. The COM and DCOM communications transport between the client program and the resident external controlling interface is operated in an asynchronous manner, namely providing an acknowledgement thereby releasing the communications transport to accept further communications prior to the actual execution of the command. The combination of the synchronous and the asynchronous data communication for the commands provides the benefit that the operator considers the commands to occur nearly instantaneously while permitting the resident external controlling interface to verify that the command is proper and cause the commands to execute in a controlled manner by the digital command stations, all without additional high-speed communication networks. Moreover, for traditional distributed software execution there is no motivation to provide an acknowledgment prior to the execution of the command because the command executes quickly and most commands are sequential in nature. In other words, the execution of the next command is dependent upon proper execution of the prior command so there would be no motivation to provide an acknowledgment prior to its actual execution.